All of this comes after Gov. Rick Snyder and the Republican legislature announced a bill that would make Michigan the country's 24th right-to-work state. The legislation is bound to set up a heated confrontation between union activists and the legislature.

Update at 9:15 p.m. ET. Senate Passes Its Own Bills:

The state Senate approved two of its own right-to-work measures — one for public employees and the other for private employees, Detroit Free Press reports. As we noted in an earlier update, the chambers will now have to wait for further action.

(Update at 5:11 p.m. ET: The House has passed the legislation. It is now headed to the Senate, which by law has to wait five days before taking a vote.)

"'I think this is what's best for Michigan,' the GOP governor said while flanked by House Speaker Jase Bolger, Senate Majority Leader Randy Richardville, Lt. Brian Calley and three union members who support the law.

"'I do not view this as something against the unions,' Snyder said, saying it's about making sure 'workers have the right to chose who they associate with.'

"Police and fire unions would not be affected by the new law. Snyder cited the dangers of their jobs and their 'special bond and connection.'"

If this bill becomes law, paying union dues would become optional.

The Lansing State Journal reports that Snyder made the announcement after talks between him and union leaders "about heading off right-to-work legislation broke off Wednesday."

The Free Press posted video of the protests inside the state house. It shows demonstrators shouting on several levels of the rotunda. They grew louder as state police moved into the chambers to control the situation inside.

The images were very much reminiscent of what we saw in Wisconsin in 2011, when Gov. Scott Walker and his legislature introduced and passed a measure severely limiting the rights of public employees to bargain collectively. As you know, that was a protracted affair that culminated in a recall election that Walker won.

Reuters reports that Republican lawmakers believe there are enough votes to pass the measure. The wire service adds that in November, Michigan voters rejected a "measure that would have enshrined a right to collective bargaining in the state constitution."

Update at 4:50 p.m. ET. A Walkout, A Vote:

NPR's Ken Barcus, who is following the situation in Michigan, tells us that Democratic lawmakers have walked out of the House in protest.

"They are going to try to open the doors to the state Capitol to let protesters in," Ken tells us. Capitol Building managers said they were readying for that to happen and were waiting for state troopers to get in their place.

Ken adds:

"Tonight, the state House and the state Senate are expected to approve the bills in front of them. Then the chambers swap the bills. Procedurally, neither can take up the legislation until five days have elapsed. (It's in the state constitution — legislation must "lay over" in a chamber for five days before it can be voted on for a first time.) So this can't become official until sometime next week, but it appears to be a fait accompli."